This site is targeted at medical and radiology professionals, contains
user contributed content, and material that may be confusing to a lay
audience. Use of this site implies acceptance of our
The cobweb sign is seen in cases of arterial dissection (usually aortic dissection) on CTA examinations and represents strands or ribbons of media crossing the false lumen, and appearing as thin filiform filling defects.
Although it is a specific sign for the false lumen, it is infrequently seen (thus low sensitivity).
The version of Internet
Explorer you are using is not supported. Download links for more modern
web browsers are provided below.
If you do not have administrator rights to update your browser you may
want to use a portable browser, either from a USB flash drive or a